Various techniques have been employed to achieve the preparation of porous coatings using colloidal particles. They can be classified in laser techniques [Hua1, Li1], classical colloidal, or nanosphere, lithography [Ko1, Jia3, Den2, Ryb1], soft lithography [Cho2], three-dimension particle template deposition and infiltration techniques [Jia1, Par, Sch, Hyo1, Bar] or one-step deposition techniques [Kan1, Xu1]. The references between square brackets are copied below:    [Jia1] P. Jiang, “Surface-templated nanostructured films with two-dimensional ordered arrays of voids”, Ange. Chem. Int. Ed. 2004, 43, 5625-5628.    [Hua] S. M. Huang, M. H. Hong, B. S. Luk'yanchuk, Y. W. Zheng, W. D. Song, Y. F. Lu, T. C. Chong, “Pulsed laser-assisted surface structuring with optical near-field ehanced effects”, J. Appl. Phys. 2002, 92(5), 2495-2500.    [Ko] H.-Y. Ko, H.-W. Lee, J. Moon, “Fabrication of colloidal self-assembled monolayers (SAM) using monodisperse silica and its use as a lithographic mask”, Thin Solid Films 2004, 447-448, 638-644.    [Sch] R. C. Schroden, M. Al-Daous, C. F. Blanford, A. Stein, “Optical properties of inverse opal photonic crystals”, Chem. Mater. 2002, 12, 3305-3315.    [Jia2] P. Jiang, M. J. McFarland, “Wafer-scale periodic nanohole arrays templated from two-dimensional nonclose-packed colloidal crystals”, J. Am. Chem. Soc. 2004, 127, 3710-3711.    [Kan] M. Kanungo, M. M. Collinson, “Fabrication of two-dimensionally ordered macroporous silica materials with controllable dimensions”, Chem. Comm. 2004, 548-549.    [Li] L. P. Li, Y. F. Lu, D. W. Doerr, D. R. Alexander, J. Shi, J. C. Li, “Fabrication of hemispherical cavity arrays on silicon substrates using laser-assisted nanoimprinting of self-assembled particles”, Nanotechnology 2004, 15, 333-336.    [Par] K.-H. Park, I.-K. Sung, D.-P. Kim, “A facile route to prepare high surface area mesoporous SiC from SiO2 sphere templates”, J. Mater. Chem. 2004, 14 3436-3439.    [Bri] E. P. Briggs, A. R. Walpole, P. R. Wilshaw, M. Karlsson, E Palsgard, “Formation of highly adherent nano-porous alumina on Ti-based substrates: a novel bone implant coating”, J. Mater. Sci.: Mat. Med. 2004, 15, 1021-2029.    [Den] F. A. Denis, P. Hanarp, D. S. Sutherland, Y. F. Dufrêne, “Nanoscale chemical patterns fabricated by using colloidal lithography and self-assembled monolayers”, Langmuir 2004, 20, 9335-9339.    [Cho] D.-G. Choi, S. G. Jang, H. K. Yu, S.-M. Yang, “Two-dimensional polymer nanopattern by using particle-assisted soft lithography”, Chem. Mater. 2004, 16, 3410-3413.    [Ryb] J. Rybczynski, U. Ebels, M. Giersig, “Large-scale, 2D arrays of magnetic nanoparticles”, Col. Surf. A: Physicochem. Eng. Aspects, 2003, 219, 1-6.    [Xu] H. Xu, W. A. Goedel, “Polymer-silica hybrid monolayers as precursors for ultrathin free-standing porous membranes”, Langmuir 2002, 18(6), 2363-2367.    [Hyo1] T. Hyodo, K. Sasahara, Y. Shimizu, M. Egashira, “Preparation of macroporous SnO2 films using PMMA microspheres and their sensing properties to NOx and H2”, Sens. Act. B 2005, 106, 580-590.    [Bar] P. N. Bartlett, J. J. Baumberg, P. R. Birkin, M. A. Ghanem, M. C. Netti, “Highly ordered macroporous gold and platinum films formed by electrochemical deposition through templates assembled from submicron diameter monodisperse polystyrene spheres”, Chem. Mater. 2002, 14, 2199-2208.